Lamp socket having means to releasably lock the end of a fluorescent lamp therein



J. FALLEK LAMP SOCKET HAVING MEANS T0 RELEASABLY LOCK THE END OF A FLUORESCENT LAMP THEREIN Filed July 21, 1949 Oct. 2, 1951 wM/M f -Ivar a Ex/ 3% Patentecl Oct. 2, 1951 LAIHP SOCKET HAVING MEANS TO RELEAS- ABLY LOCK THE END OF A FLUORESCENT LAMP THEREIN Joseph Fallek, Chicago, Ill.

Application July 21, 1949, Serial No.- 105,976

a l .ThiS invention relates in general to a new and improved form of fluorescent light socket and is particularly concerned with a novel device for positively locking in place the ends of the fluorescent bulb or tube to prevent removal thereof. Heretofore there have been various designs of sockets for fluorescent tubes, but certain inherent disadvantages are present in these sockets which make them unsatisfactory for commercial use. The socket design which has been most acceptable commercially heretofore consists of two spaced apart contact arms which are adapted to spring apart when the tube is inserted and to clamp the tube in place merely by the resiliency of these contact arms. In this type of structure when the tube is inserted, the ends of the tube .move inwardly in the socket and the tube is then rotated through an angle of approximately 9.0". This rotation of the tube forces the spring arms apart until the contact pinson each end of the tube'come to rest in notches in the contact arms. This procedure results in a wearing of certain parts within the socket so that after the fixture has been in use for some time and a number of replacements have been made, these sockets will no longer hold the fluorescent tube in place. Furthermore, the worn places within the socket cause a. considerable amount of play as between the contact pins on the end of the tube and the contact arms so that a poor electrical contact is made, resulting in a flickering of the light and unsatisfactory performance thereof.

This wearing of parts results primarily from the rotation of the contact pins within the socket housing where they come in contact with a part of the housing and thus wear this part by frictional contact therewith.

The present invention is designed to overcome these and other disadvantages inherent in fluorescent light sockets heretofore known. The device disclosed herein contains no wearing parts and no part of the housing will become worn because the contact pins on the ends of the fluorescent tubedo not come in contact with any part of the housing.

In view of the foregoing, it is a principal object of the present invention to provide a fluorescent light socket which has mechanism therein for firmly and positively holding the fluorescent tube against inadvertent removal therefrom.

Another object of the invention is to provide a fluorescent light socket wherein the contact pins on each end of the fluorescent tube may be manually released for removal.

4 Claims (Cl. 173-328) A further object of the invention is to provide a light socket adapted to receive and hold the contact pins of a fluorescent lighting tube wherein the spaced apart pins on each end of the tube may be inserted in the socket merely by traversing an elongated slot therein after which releasable locking means may be caused to positively lock the tube in place. Still another and more specific object of the invention is to provide a fluorescent light socket wherein one of the contact arms is stationary and the other contact arm is movable, the movable contact arm having thereon a portion which acts as a locking member for locking the end of the fluorescent tube firmly and positively within the socket.

Still another object of the invention is to provide a fluorescent light socket wherein one of the contact arms'is movable into and out of a locking position for locking the fluorescent tube in place, and wherein a manually movable releasing member may be actuated to move the movable contact arm out of locking position for insertion or removal of the fluorescent tube.

Other objects and advantages of the invention will become apparent from reading the following description taken in conjunction with the accompanyin drawing in which:

Fig. 1 is an exploded view of a pair of light sockets embodying the present invention illustrating a fluorescent tube located therebetween; Fig. 2 is an exploded view of the light socket embodying the present invention showing the relationship between the socket body, the contact arms and the releasing lever;

Fig. 3 is an elevational view of the light socket looking toward the inner side thereof;

Fig. 4 is an elevational view of the light socket from the opposite side with the cover plate removed to show the details of construction;

Fig, 5 is an enlarged horizontal sectional view taken substantially alon the plane of line 55 of Fig. 4;

Fig. 6 is a fragmentary vertical sectional view taken substantially along the plane of line 6-6 of Fig. 5 and showing the two contact pins at one end of the fluorescent tube locked inposition; 1

Fig. 7 is a fragmentary view similar to Fig. 6 illustrating the movable contact arm in released position; and A l i Fig. 8 is an elevationalview of a modified form of the movable contact arm.

Referring now more particularly to the drawing, Fig. 1 shows a pair of the light sockets embodying the present invention in spaced apart relation as they would appear on a fixture, each such socket bein indicated generally by the numeral I. A fluorescent lighting tube 2 is shown extending between the two sockets I and illustrates the upper and lower contact pins 3 and 4 at each end thereof.

The body 5 of the socket is provided with an elongated slot 6 adapted to receive and hold the contact pins 3 and 4.

As may be seen more clearly in Fig. 2, the main body 5 of the socket has a partition I extending longitudinally and centrally thereof providing the cavities 8 and 9 on opposite sides. Near the lower end of the central partition I, it is provided with an opening I below which there is another opening II for a purpose which will be presently described. The outer edge of the body adjacent the lower end thereof is provided with a cut-out portion I2 to provide ample, space for the releasing lever to be moved and actuate the movable contact arm between its locking and releasing positions.

The stationary contact arm is indicated by the numeral I3 and consists of an upper flat Dortion l4 which threadedly receives a contact screw I5 which constitutes a binding post by means of which the contact arm may have attached thereto the bared end of one of a pair of conductor wires (not shown). This arm then has a downwardly extending portion I6 which terminates at its lower end in the spaced apart sections I1 and I8 thereby providing a recess I9 within which the upper contact pin 3 may be received.

The movable arm is indicated generally at and consists of a similar fiat portion 2I at the top thereof which threadcdly receives therein a contact screw 22 which constitutes a binding post for attachment thereto of the bared end of the second conductor wire (not shown). This arm then has a downwardly extending portion 23 which is offset slightly and terminates in an inwardly extending portion 24. Immediately adjacent this terminal portion 24 and the bottom of the arm 23 there is provided a suitable stop member 25. The lower contact pin 4 is adapted to rest on the terminal portion 24 and is prevented from any side movement by means of the stop 25.

The contact arm I3 is disposed within the main body 5 in the cavity 8. The terminal flanges I1 and I8 at the lower end thereof are received within the opening III in the central partition 1 whereby the recess I9 will be positioned at the upper end of the elongated slot 6.

The movable contact arm 20 is inserted and secured within the cavity 9 of the main body 5 and has the lower .terminal portion 24 thereof extending through the opening II in the central partition I. A coiled compression spring 26 is disposed within the cavity 9, bearing at one end against the inner wall of the body 5 and at its other end against the downwardly extending portion 23 of the movable arm 20, as shown in Figs. 4 and 6. This spring 26 normally urges the movable contact arm 20 into looking position at all times.

The releasing lever 21 is provided with two rearwardly extending pins 28 and 29. The upper pin 28 is received by the opening 30 in the central partition I and acts as a pivot about which the lever may move to urge the contact arm 20 out of its locking position.

The lower pin 29 is received within the housing 5 so that it is partially surrounded by a cut-away portion 3| in the partition I and is also partially surrounded at the opposite side thereof by the curved connecting portion 32 of the contact arm 20 which is positioned between the downwardly extending portion 23 and the stop 25 thereof (Figs. 6 and 7) The lower end of the lever 21 may, if desired, be provided with an offset portion 33 against which pressure may be applied for pivoting the lever about its upper pivot pin against the compression of the coiled spring 26. This offset portion 33, however, may be dispensed with and the lever may consist merely of a flat plate with the two pins protruding therefrom.

Fig. 6 illustrates the contact arms I3 and 20 in their normal positions within the housing 5. The upper and lower contact pins 3 and 4 at the end of the fluorescent tube are also shown in position within the housing where the upper contact pin 3 bears against the sides of the recess I9. The lower contact pin 4 will bear downwardly against the lower terminal portion 24 of the arm 20. The upper pivot pin 28 on the lever 21 is shown in position within the opening 30 and the lower pin 29 of the lever is shown in position partially surrounded by the curved section 32 of the contact arm 20. It will be observed from viewing Fig. 6 that the structure forms a firm and secure lock for holding in place the ends of the fluorescent tube. The tube can not be removed by force because of the lower terminal portion 24 of contact arm 20. When it is desired to release the tube and remove it from the socket, pressure against the bottom of the lever 21 may be applied suflicient to overcome the force of spring 26, whereupon the various parts will assume the position shown in Fig. 'I. Pivotal movement of the lever 21 about the upper pin 28 will move the lower pin 29 outwardly against the downwardly extending portion 23 of the movable contact arm 20, whereupon the lower terminal portion 24 of the arm 20 will be retracted through the opening I I to provide a clear path in the slot 6 for inward or outward traverse of the contact pins 3 and 4 on the ends of the fluorescent tube.

Fig. 8 illustrates a modified form of movable contact arm 20 and may be indicated generally by the numeral 34. In this form of the invention,- the contact arm is formed of two sections 35 and connection is made between the two sections of: the arm by means of the connecting link 38. In

this case the Spring 31 takes the place oi. the coiled spring 26 in the preferred form of the invention. The operation of this arm is identical with that explained above in connection with the arm 20. The lower end of the arm 34 is formed in the same manner by having the bottom terminal portion 39 against which the lower contact pin 4 of the fluorescent tube may bear for electrical contact. A stop portion 40 is formed at one side of the terminal portion 39 and the curved section 4| is utilized to partially surround the lower pin 29 on the releasing lever whereby movement of the lever will move the lower section 38 of the arm out of the path of the contact pins on the fluorescent tube.

An important advantage residingin the present construction is that it is so designed as to be applied to fixtures already in use without modification. When the fluorescent tube is to be applied in position between the two sockets, one end of the tube may be inserted by a longitudinal movement of the tube, whereb the upper and lower contact pins 3 and 4 will be received by the slot 8 and position these contact pins against the sides of the recess I! in the arm I: and against the terminal portion 24 of the contact arm ill. The other end of the tube may then be inserted in the opposite socket after the lever 21 has been moved to withdraw the terminal portion 24 of the arm from the slot 6. The contact pins 3 and 4 may then be caused to traverse the slot 6 to position the upper. contact pin 3 in the recess it, after which pressure on the lever 21 may be released and the spring 28 will then force the arm 20 back into locking position. In the case of the modified form shown in Fig. 8. the spring 31 will act to force the arm back into looking position.

It will thus be seen that the contact pins at th ends of the fluorescent tube do not touch the housing and therefore there will be nothing to cause any wearing within the housing. Because of. the force of the springagainst the movable contact arm 20, the contact pins on the tube will be held firmly in place and the upper pin will be held securely in contact with the sides of the recess i9. These forces cooperate to provide a perfect electrical contact for the two pins.

Unlike sockets of this nature heretofore used. the present design provides for a better electrical contact between the arms and pins. The upper pin will have contact with its corresponding arm on three sides thereof, and the lower pin will have contact with its arm on two sides thereof. It will be impossible to remove the fluorescent tube from either socket until movement of the releasing lever 21 is efiected from its locking position.

The invention resides primarily in the provision of at least one movable contact arm which normally locks the contact pins against removal. The means for moving the contact arm between locking and released positions may vary and take other specific forms from that shown herein. In the present instance the releasing lever 21 will traverse the cut-away portion i2 in the body I and will be limited in its movement by the ends of such cut-away portion. This portion I! will form a slot when the cover of the body is secured in place.

Changes may be made in the form, construction and arrangement of parts from that disclosed herein without in any way departing from the spirit of the invention or sacrificing any of the attendant advantages hereof, provided, however, that such changes fall within the scope of the claims appended hereto.

The invention is hereby claimed as follows:

1. A light socket for fluorescent light tubes wherein the tube has a pair of contact pins at each end thereof, comprising a main body portion, an elongated slot extending inwardly from one end of said body, electrical contact means at the inner end of said slot adapted to straddle and frictionally receive one of the contact pins on the light tube, an electrical contact member adjacent the open end of said slot and movable from an advanced position across the slot to positively lock one end of the light tube therein to a retracted position clear of said slot, and a lever having one end pivotally mounted within said body and having a medial portion thereof movable into engagement with said contact member and having an end region thereof extending outside of said body for manual engagement to move said medial portion into engagement with said last named contact member to move the latter out of said slot whereby that end of the light tube may be-released.

2. A light socket for fluorescent light tubes wherein the tube has a pair of contact pins at each end thereof, comprising a main body portion, there being an elongated slot extending inwardly from one end of said body, a stationary contact arm secured on one side of and within said body, one end of said arm extendinginto said slot adjacent the inner end thereof and being shaped to provide a recess adapted to frics tionally receive one of the contact pins on the light tube, a movable contact arm positioned within and on the opposite side of said body and having a terminal portion thereon adapted for electrical contact with the other contact pin on; the tube, yieldable means normally urging said terminal portion toward a position extending across'said slot adjacent the open end thereof, whereby to lock the tube against removal, and a releasing lever having two spaced pins thereon, one of said pins being received within an opening within said body to permit pivotal movement of the lever, and the other pin adapted to come against said movable contact arm to remove the terminal portion thereof from said slot when the lever is pivoted against the pressure exerted by said yieldable means, whereby to permit insertion or removal of the adjacent end of the light tube, a portion of said lever projecting beyond the confines of said main body portion and being thus accessible for manipulation thereof.

3. A light socket for fluorescent light tubes wherein the tube has a pair of contact pins at each end thereof, comprising a main body portion, a centrally disposed partition extending longitudinally of said body portion, thereby to provide a cavity on each side of the partition, an elongated slot extending longitudinally of said partition and open at one end thereof, a stationary contact arm secured in one of said cavities, one end of said arm having a recess therein positioned adjacent the closed end of said slot to receive one of the contact pins on the end of the light tube, a movable contact arm positioned in the other of said cavities having a terminal portion thereon adapted for electrical contact with the other contact pin on the light tube, yieldable means normally urging said terminal portion toward a position extending across said slot adjacent the open end thereof to lock the light tube against removal, and a releasing lever having two spaced pins thereon, one of said pins being received in an opening in said partition for pivotally mounting the lever, and the other pin adapted to come against said movable contact arm to remove the terminal portion thereof from said slot when the lever is pivoted against the force of said yieldable means, whereby to permit insertion or removal of the adjacent end of the light tube, said lever having a portion thereof extending beyond the confines of said main body portion whereby the lever is accessible for manipulation.

4. A light socket for fluorescent light tubes wherein the tube has a pair of contact pins at each end thereof, comprising a main body portion, there being an elongated slot extending inwardly from one end of saidbody, a stationary contact arm secured on one side of and within said body, one end of said arm having a recess therein positioned adjacent the inner end of said slot tofrictionally receive one of the contact pins on the light tube, a movable contact arm positioned within and on the opposite side of said body and having a terminal portion thereon adaptedfor electrical contact with the other contact-pin on the tube, said movable contact arm including two spaced apart sections, a yieldable member connecting said two sections together, whereby said terminal portion of the arm is normally urged to a position across said slot to lock the adjacent end of the light tube against removal, an electrical connector also extending between .the two sections of said arm and electrically connectingsaid sections together and a re- 'from said slot when the lever is moved against the action of said yieldable, member to permit insertion or removal of the adjacent end of the 8' light tube, an end of said lever projecting outwardly beyond said main body portion whereby the lever is accessible for manipulation.

JOSEPH FALLEK.

REFERENCES CITED The following references are of record in the file or this patent:

U NITED STATES PATENTS Number Name Date I 1,626,580 Finizio Aug. 26, 1927 1,746,650 Harrington Feb. 11, 19.30 2,051,702 Gueflroy Aug. 18, 1936 2,223,172 George Nov. 26, 1940 2,254,222 Hubbell Sept. 2, 1941 2,282,875 Mueller May -12, 1942 2,408,551 Frank Oct. 1, 1946 

